Shining infrared light on cancer speeds diagnosis

To look for cancer in a biopsy, the sample is stained to highlight DNA and a protein in cytoplasm. Cancer cells contain a higher ratio of DNA to protein and a larger nucleus, making it possible to judge whether cancer is present.

To make things more objective, Chris Phillips and his colleagues at Imperial College London used light. The chemical bonds in each molecule absorb infrared light of a characteristic wavelength. By measuring the level of absorption, the amount of DNA and protein in a sample can be calculated.